function Parent() {

}

Child.prototype = new Parent()
function Child() {

}

class Test {
    #b = 2 // # == staic
    a = 1
    constructor(age) {
        this.age = age
    }

    run() {

    }

    static eat() {

    }
}

class Test2 extends Test {
    constructor(name, num) {
        super(num)
        this.name = name
    }
}

let t = new Test2('tom', 19)